The Four Worlds
The Kabbalah knows four Worlds. Although they exist simultaneously, one flows forth from the other. The Tree of Life exists in each of the four Worlds, and at the same time it has four divisions structurally corresponding to each of the four Worlds. First, let us have a look at what those four Worlds are.
Atziluth is the World of Emanation. It is the first world that emanated from the Divine. Emanation means that it flowed forth from the Divine. It is not the same as creation. Creation implies an act of creating, that will take place in the next World.
Atziluth is the World of Primal Concepts, Emanations, Radiations. It contains the unlimited divine energy in the form of primal archetypes. Here the Divine is present and is active. Here is the divine essence of all things and beings, the primal will, and pure consciousness. It is the eternal unchanging world. It is the world of unity.
In this world the will to create is born. Here are the seeds, the essence, of all the worlds to follow.
In man Atziluth brings forth thoughts and concepts, and the will.
Atziluth corresponds to the element of Fire, the element that transforms everything into its essence.
Ehieh and Shekinah, the two poles of our consciousness unite in Atziluth.
Briah is the World of Creation. The ideas, the concepts that arise in Atziluth now are being clothed with subtle substance. This is the act of creation. In Atziluth the Divine itself is present and 'acts'. In Briah the Divine works through the archangels who condense the archetypes and prepare them for further creation work by lower order beings.
Leaving the divine world of Atziluth, in Briah duality arises, space-time, male-female and so on.
In man Briah corresponds to the Spirit.
In Atziluth we had non-being, in Briah we get the sense of being.
The condensation of energy in Briah makes this world correspond to the element of Air.
Yetzirah is the World of Form. It is the world of procreation and movement, of development. Here the Divine works through the Angels. The Angels give form to the energies of Briah. They each specialize in one particular aspect of the creation work.
In man Yetzirah correponds to the Heart.
Further condensation of the energies makes Yetzirah correspond to the element of Water.
Assiah is the World of Action. It is the world of happenings, appearances, phenomena, the world of becoming. It is our physical world, crystallized to a state of solidity, making Assiah correspond the element of Earth. With the term 'physical world' we also understand the spiritual energies pertaining to the laws of nature.
In Assiah one expresses oneself as an individual being with a self consciousness.
In the human body Assiah corresponds to the physical body.
The four Worlds also correspond to the four letter of the word YHWH (Yahweh): Yod for Atziluth, Heh for Briah, Waw for Yetzirah and Heh for Assiah. Here are some more correspondences:
World of Emanation
World of Creation
World of Form
World of Action
the archetype of heavenly man
man becomes manifest, creation, genesis
man placed in the Garden of Eden
man expelled from Eden into the physical world